Circuit interrupter



May 21, 1935- w. M. AUSTIN 2,001,898

CIRCUIT INTERRUPTER Filed Jan. 8, 1919 l WITNESSESI WJ/er M' Ausf/nPatented May 2l, 1935 PATENT OFFICE cmcurr INTERRUPTER Walter M. Austin,Swissvale, Pa., assigner to Westinghouse Electric & ManufacturingCompany a corporation of Pennsylvania Application January 8, 1919,Serial No. 270,110 13 claims. (ci. zoo-109) My invention relates toelectrical protective devices and particularly to latch mechanisms forcircuit interrupters. r

The object of my invention is to provide a device ofthe above indicatedvcharacter that shall be simple and durable in construction and eiectivein operation and that may not be actuated to undesirably open theinterrupter when subjected to heavy jarring.y

In practicing my invention, I provide a latch mechanism comprising mainand auxiliary interdependent movable latch members, the auxiliary memberbeing biased toward its latching position in engagement with the mainmember that engages the movable arm ora circuit interrupter and isbiased towards its releasing position. The latch members are so formedand related as to requirea relatively slight actuating force and are sopositively positioned as to be protected against 20 accidental releaseby jarring.

Figure 1 of the accompanying drawing is a view, partially in sideelevation and partially in section, of a circuit interrupter embodyingmy invention, and Fig. 2 is a detail View, on an enlarged scale, ofportions of the device shown in Fig. 1. f

A circuit interrupter I is -mounted upon a panel 2 and comprises twomain stationary contact members 3 and 4, auxiliary stationary contactmembers 5 and 6 and brackets 1, only one of which is shown, upon whichare pivotally mounted an arm 8 carrying a. movable contact member 9 vforengaging the member 6 and a second movable arm I8 comprising aresilientlymounted member II for engaging the member 5, a laminatedbridging member I2 that is pivotally mounted thereon, and a cam memberI3. The lever arm I0, pivotally connected to the brackets 1 by a pin 2|,is connected to the member I2 by a pin I4 and to the arm 8 by aspring-and-rod connection I5. An operating lever arm I6 has a rollermember I1 at one end thereof for engaging the cam memberr I3, and twoprojections vI8 and I9 that extend substantially at right anglestherefrom. Springs 28 connect the projections I8tothearm I0.

The pin 2| and a pin 22 extend between the brackets 1 and support a pairof stationary plates 23, only one of rwhich is shown, to which pins 24and 25 are held. A latch member 26, pivoted on the pin 25, has a,relatively short arm 21, in which oppositely facing shoulders 28 and 29are formed for engagement with an adjustable latchengaging member 30 onthe projection I9 anda y 55 relatively long arm 3| for engagement with adetent 32 on a trigger 33 pivoted on the rod 22. The member 30 comprisesa threaded bolt 34 positionedin a threaded recess in the end of theprojection I9 where it is held in adjusted position by a lock nut 35.

A rcurved lug 36, on the trigger 33, bearing against the pink 24,thereby limits the counterclockwise turning movement of the trigger, asviewed inthe drawing, and serves as a support for one end of a spring 31that is joined, at its 10 other end, to a lug 38 on the latch member 26and tends to turn the latter in a clockwise direction.

The trigger 33 has a projection 39 that extends to a position adjacentthe arm I0 and operates, in co-operation with the latter, to prevent thel5 resetting of the latch member 26 to the position shown when theinterrupter is in its open position.

An armature member 40, for co-operation with pole pieces 4I of anelectromagnet 42, comprises 20 arms 43, only one of which is shown,pivoted on the pin 22, a projection 44, to which a rod 45 andbalance-Weight members 46 are attached, and a bridging portion 41extending between the arms 43 and which also has a shoulder 48 formed 25thereon for tripping engagement with a projection 49 on the trigger 33.

A hand-tripping mechanism comprises a handle 50 attached to a lever 5Ipivoted on the pin 22. The lever 5I has an arm 52 to engage the 30trigger 33. A projection 53 on the lever 5I engages one end of a bracket54 on the panel 2 to limit the movement of the lever 5I'.

A calibrating mechanism comprises a bifurcated depending member 55 thatis attached to 35 the pin 22 by arms 56 and carries a calibrated scaleplate 51. A screw-threaded rod 58, loosely mounted at its ends in spacedoffset portions 58 of the member 55, has a handle 60 at one end andcarries a traveling nut 6I having a pointer 40 62 for co-operation withthe scale plate 51. A lever 63, loosely pivoted, at its ends, to thebracket 54 and the nut 6I, respectively, pivotally supports a dash pot64. Numeral 64 indicates a piston between which and a pin 65 in one ofthe 45 arms 43, a link 66 extends.

When the interrupter is actuated to its closed position, the operatinglever arm I6 is turned in a clockwise direction until the member 30`engages the shoulder 28 of the latch member 26. Fur- 50 ther movementof the arm I6 causes the member 26 to rotate in a counter-clockwisedirection about the pin A25 until the detent 32, by reason of thedisposition of the spring 31 between the lugs 36 and 38, is snapped intothe position, with respect 55 to the arm 3i of the member 26, shown inthe drawing.

During the above described movements, the shoulder 29 is interposed inposition behind the member 30 to latch the interrupter in its closedposition, as shown in the drawing.

To prevent the inadvertent resetting of the latch member 2S to itslatching position while the interrupter is in its open position, whichresetting, upon the attempted closing of the interrupter, would causethe member 30 to be jammed against the outer end of the arm 2l, withpossible consequent damage to the members thus engaged, the projection38 on the trigger 33 is interposed in the path of movement of the armi0. The latter, in the open position of the interrupter, bears againstthe projection 39 and, thereby, the detent 32 is held in position out ofthe path of movement of the arm 3l. During the operation of closing theinterrupter, the projection 3S will be released to permit the trigger toassume its operative position.

By reason of the proportions and relation of the arms 2l and 3l of thelatch member 25, the force exerted by the member 30 against the shoulder29 will be considerably reduced between the arm 3l and the detent 32,thereby permitting the magnet 42 to be smaller than would otherwise benecessary. The reduction of the force between the arm 3| and the detent32 permits the spring 3l to be of a relatively high-tension value which,taken in conjunction with the relatively small mass of the trigger 33,causes the latter to be highly resistive to heavy vibrations, such asjarring.

The arrangement provides a simple, economical and positive latchmechanism and particularly adapts the interrupter for effective servicein positions subject to heavy vibrations, such as aboard war ships.

While I have shown and described a particular form of my invention,changes may be effected therein, without departing from the spirit andscope thereof, as set forth in the appended claims.

I claim as my invention:

1. In a circuit interrupter, the combination with a movablecontact-carrying arm and an operating lever therefor, of a latchmechanism comprising an adjustable stop-member disposed on said lever, apivoted main latch member having arms of diiierent lengths, the shorterof which has a pair of oppositely disposed shoulders thereon forengagement with said stop member, a pivoted auxiliary latch member forengagement with the longer of the said main latch arms and having aprojection, said projection extending to a position adjacent saidcontact-carrying arm to prevent the operation of said auxiliary latchmember when the interrupter is in its open position, a spring connectingsaid latch members, a stop member for said auxiliary latch membery andmeans for operating said auxiliary latch member.

2. In a circuit interrupter, the combination with a movablecontact-carrying arm and an operating lever therefor, of a latchmechanism comprising a pivoted main latch member having arms ofdifferent lengths, a pivoted auxiliary latch member for co-operationwith said main latch member and having means co-operating with saidcontact-carrying arm to prevent the operation of said auxiliary latchmember when the interrupter is in its open position, resilient meansbiasing said latch members in opposite directions about the pivotsthereof, and means for releasing said latch members.

3. In a circuit interrupter, the combination with a movable member, of alatch mechanism therefor comprising a pair of interdependent movablelatch members, a single means for biasing said latch members towardpredetermined positions, and means including the movable memberrstmentioned for preventing the setting of said latch members in thelatched co-operative relation thereof while the interrupter is in itsopen position.

4. In a circuit interrupter, the combination with a movable member', ofa latch mechanism therefor comprising a plurality of co-operating latchmembers, and means for preventing the movement of one of the latchmembers to its latching position while the interrupter is in openposition independently of current values controlling the circuitinterrupter.

5. An electric switch comprising a movable contact member biased tocircuit-opening position, main latching means for restraining saidcontact member in circuit-closing position, auxiliary latching meanshaving a portion adapted to engage and hold said main latching means inlatching position, and a resilient connection between said main andauxiliary latching means arranged to bias said auxiliary latching meansto latchengaging position and means for holding said auxiliary latchingmeans out of latching engagement with said main latching means when saidmain latching means is not in latching position.

6. An electric switch comprising a movable contact member biased tocircuit-opening position, an operating member adapted to be operated tomove said contact member to circuit-closing position, a main latchingmember for engaging and restraining said operating member to cause thesame to hold said contact member in circuitclosing position, anauxiliary latching member of relatively small mass adapted to engage andhold said main latching member in latching position, and a springinterconnecting said main and auxiliary latching members and arranged tobias said auxiliary latching member to latch-engaging position with alarge force whereby said auxiliary latching member is substantiallyshock-proof,

and means including a portion engageable with said auxiliary latchingmember for holding said auxiliary latching member out of latchingengagement with said main latching member when said movable contactmember is in circuit-opening position and said main latching member isout of restraining engagement with said operating member.

7. In a circuit interrupter, the combination with a movable memberbiased to open position, of a latch mechanism therefor comprising a.plurality of cooperating latch members, one of said latch members beingengageable with said movable member, and another of said latch membersbeing engageable with the rst said latch member for latching it inengagement with said movable member, and means for preventing themovement of the second of said latch members to its latching positionwhile the interrupter is in its open position with the first said latchmember disengaged from said movable member independently of currentvalues controlling the circuit interrupter.

8. In a circuit interrupter, the combination with a movable memberbiased to open position, of a latch mechanism therefor comprising aplurality of cooperating latch members, one of said latch members beingengageable with said movable member, and another of said latch membersbeing engageable with the first said latch member for latching it inengagement with said movable member, a spring connectedbetween saidfirst and second latch members for biasing both of said latch members,and means for preventing the movement of the second of said latchmembers to its latching position while the interrupter is in its openposition with the first said latch member ydisengaged from said movablemember independently of current values controlling the circuitinterrupter.

9. In a circuit interrupter, a contact movable to open and close thecircuit, a member movable upon actuation of said contact, means forbiasing said contact and said movable member to move to open-circuitposition, a latch member engageable with said movable member, a secondlatch rmember engageable with the first said latch member for holding itin engagement with said ymovable member, electro-responsive means forcausing movement of said second latch member out of engagement with saidfirst latch member and thereby permitting said first latch member todisengage said movable member and allow it and said contact to move toopen-circuit position, and means for engaging said second latch memberand holding it in disengaged position at least for an interval of timeprior to each re-engagement of said first latch member with said movablemember.

l0. In a circuit interrupter, a contact movable to open and close thecircuit, a member movable upon the actuation of said contact and havinga catch portion thereon, means for biasing said contact and said movablemember to move to open-circuit position, a latch member for engagingsaid catch portion on the movable member and holding said movable memberagainst its bias, said catch portion on ,the movable member exerting aforce on said latch member capable of moving said latch member todisengaged position, a catch portion on said latch member, a secondlatch member for engaging said catch portion on the first said latchmember and holding the rst said latch member in engagement with saidcatch portion on the movable member against the force exerted on thefirst said latch member, electro-responsive means for causing movementof said second latch member out of engagement with said catch portion onthe first latch member and thereby permitting said first latch member todisengage said catch portion on the movable member and allow saidmovable member and said contact to move to open circuit position, andmeans for holding said second latch member out of latchlng engagementwith the catch on said first latch member at least until shortly beforesaid rst latch member is re-engaged with the catch portion on themovable member.

1l. In a circuit interrupter, a contact movable to open and close thecircuit, a member movable upon the actuation of said contact and havinga catch portion thereon, means for biasing said contact and said movablemember to move to opencircuit position, a pivoted latch member forengaging said catch portion on the movable member and holding saidmovable member against its bias, said catch portion on the movablemember exerting aforce on said latch member capable of moving said latchmember to disengaged position and the perpendicular distance between theline of action of the force exerted by said catch portion on said latchmember and the pivot point of said latch being small, a catch portion onsaid latch member, a second latch member for engaging said catch portionon the first said latch member and holding the first said latch memberin engagement with said catch portion on the movable member against theforce exerted on the first said latch member and the perpendiculardistance between the line of action of the holding force exerted on saidfirst latch member and the pivot point thereof being large,electro-responsive means for causing movement of said second latchmember out of engagement with said catch portion on the first latchmember and thereby permittingsaid first latch member to disengage saidcatch portion on the movable member and allow said movable member andsaid contact to move to open circuit position, and means for holdingsaid second latch member out of latching engagement with the catch onsaid first latch member at least until shortly before said first latchmember is re-engaged with the catch portion on the movable member.

l2. In a circuit interrupter, a contact movable to open and close thecircuit, a member movable upon actuation of said contact, means forbiasing said Contact and said movable member to move to open-circuitposition, a latch member engageable with said movable member, a secondlatch member engageable with the first said latch member for holding itin engagement with said movable member, a spring having its endsconnected to said first and second latch members for biasing both ofsaid latch members, electro-responsive means for causing movement ofsaid second latch member out of engagement with said first latch memberand thereby permitting said first latch member to disengage said movablemember and allow it and said contact to move to open-circuit position,and means for engaging said second latch member and holding it indisengaged position at least for an interval of time prior to eachre-engagement of said first latch member with said movable member.

i3. In a circuit interrupter, a contact movable to open and close thecircuit, a member movable upon the actuation of said contact and havinga catch portion thereon, means for biasing said contact and said movablemember to move to opencircuit position, a pivoted latch member forengaging said catch portion on the movable member and holding saidmovable member against its bias, said catch portion on the movablemember exerting a force on said latch member capable of moving saidlatch member to disengaged position and the perpendicular distancebetween the line of action of the force exerted by said catch portion onsaid latch member and the pivot point of said latch being small, a catchportion on said latch member, a second latch member for engaging saidcatch portion on the first said latch member and holding the first saidlatch member in engagement with saidcatch portion on the movable memberagainst the force exerted on the first said latch member and theperpendicular distance between the line of action of the holding forceexerted on said first latch member and the pivot point thereof beinglarge, a spring having its ends connected between said first and secondlatch members for biasing both of said latch members, said springbiasing said second latch member into engagement with the first latchmember with a large force and the mass of said second latch member beingsmall whereby the likelihood of said second latch being jarred out ofengagement with said rst latch member is made small, electro-responsivemeans for causing movement of said second latch member out of engagementwith said catch portion on the first latch member and thereby permittingsaid first latch member to disengage said catch portion on the movablemember and allow said movable member and said contact to move to opencircuit position, and means for holding said second latch member out oflatching engagement with the catch on said rst latch member at leastuntil shortly before said rst latch member is re-engaged with the catchportion on the movable member.

WALTER M. AUSTIN.

